Hi, it either requires resampling by software, to sync the drifting clocks of the two cards or sync by hardware. Optimal is word clock, but sync by S/PDIF might work, too. IOW it depends on the used sound cards. Regards, Ralf _______________________________________________ Alsa-user mailing list Alsa-user@xxxxxxxxxxxxxxxxxxxxx https://lists.sourceforge.net/lists/listinfo/alsa-user